<div dir="ltr"><div>Hi Brian,</div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Tue, Jan 13, 2026 at 8:33 PM Brian Goetz <<a href="mailto:brian.goetz@oracle.com">brian.goetz@oracle.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><u></u>
<div>
<font size="4" face="monospace">While I totally understand why you
would want to do that, I don't see the connection between pattern
assignment and extending the type system to permit denotation of
quantified or existential types?</font>
</div>
</blockquote></div><div><br></div><div>Well it's kind of a loose "connection" I guess :) </div><div><br></div><div>I'm just pointing out that the two features have a common motivation: the ability to declare a variable that is initialized from some existing declared variable of an object. This is handy!</div><br><div>This idea of "local type vars" has come up before and been rejected. That's fine, but if the underlying motivations are the same, then it seems like we are being inconsistent by promoting one feature while ignoring the other. They are both useful, and for the same reason (roughly speaking), so why not complete the picture while we're mucking with the language syntax?</div><div><br></div><div>Admittedly, I'm asking not based on some conceptual language design principle, but simply because this particular omission has always bugged me and it seems relatively easy to fix without too much ugliness (maybe; to be determined).</div><div><br></div><div>-Archie</div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature">Archie L. Cobbs<br></div></div>